Tubulars storage devices, such as fingerboards, typically include a slot delimiting structure, e.g. spaced apart finger members, that define a slot capable of receiving a plurality of tubulars, e.g. drill strings. Each tubular is typically individually secured at a storage position along the slot by a corresponding latch member, which is movable between a opened and an closed position.
In some prior art tubulars storage devices, the latches are manually moved between the opened and closed positions by a worker who walks across the fingers to manually move the latches, e.g. by kicking, to the desired closed or opened position. As the finger members are often mounted at a great height (in some instances 90 feet above the drilling floor or taller) this type of manual operation of the latches by the worker is dangerous.
To overcome this dangerous situation tubular storage devices have been developed that include “automated latches” which are controlled from a remote location.
In U.S. Pat. No. 3,768,663 and U.S. Pat. No. 3,799,364 tubular storage device for use in a drilling rig are shown, wherein pivotal latch fingers are placed along the storage slot. The fingers are each connected to a hydraulic cylinder in order to selectively bring the latch into a closed position, wherein the finger extends into the path of displacement of the tubulars formed by the slot, and an opened position, wherein the finger is out of said path of displacement.
In WO 2005/061 839 an alternative storage device is shown. This device includes a so-called row controller that is connected to each of the latches for individually and sequentially moving the latches between the closed and the opened position.
In EP 2 232 000 a more recent tubular storage device is shown. This device includes a slot for storing tubulars, and a plurality of, substantially disc shaped, latch members mounted on a rotary latch members shaft. The disc shaped latch members are positioned such that they bridge the slot and thus block movement of tubulars along the slot. The disc shaped latch members are furthermore provided with recesses in their circumference. By rotating the latch member shaft, the disc shaped latch members are rotated and their recessed sections can be positioned one after the other in the slot to allow movement of a tubular along the slot. The extension thus prevent movement of the tubulars along the slot. It is noted that all latch members are rotated when the latch member shaft is rotated.